The present invention relates to a vehicle-mounted millimeter wave radar device, millimeter wave radar module, and manufacturing method thereof.
Japanese Application Patent Laid-open Publication No. Hei 7-273237A discloses the semiconductor device in which a hollow is provided around an IC chip and sealed with a structure composed of a first cap, a molded resin, and a second cap. The molded resin is cured by baking after it is covered with the second cap. Since the device has the hollow around the IC chip, it is possible to prevent IC bonding wires from being cut by thermal stress caused by plastic molding. Furthermore, deterioration of the electrical characteristic can be prevented in comparison with a device in which the IC chip is directly covered by resin, by making a hollow structure around the IC chip.
In a high frequency or other millimeter wave radar RF (Radio Frequency) module, the above conventional technology provides a hollow structure to prevent deterioration in the millimeter wave electrical characteristic. However it fails to assure adequate moisture resistance, and it cannot provide a low-cost millimeter wave radar RF module.